I am currently studying for a degree in Biology. I want to pursue this career into genetic/medical research but unfortunately this would mean being part of animal experiments (even at the lowest level it would mean fruit flies)

What should I do?

N.B Of course this is dependent on me passing my degree and getting a masters/PHD

Be realistic.Most of our actions entail mixed kamma, and we make our decisions on the balance between wholesome and unwholesome results. So it is with choice of career. If your career will aid people then it is probably right livelihood even if causing some suffering in the course of it is inevitable. Weigh it up, and take responsibility for your choices.Kim

The Buddha advised karma is intention. The Buddha also advised some forms of karma have a "trifling" result.

In my opinion, the results of karma one can only really know through meditation.

For example, when you are doing your research and, afterwards, when you meditate, do your actions come back to haunt your mind? Or does your mind feel a sense of accomplishment? Is your mind naturally at ease?

What is causing these questions on your behalf? Your inner conscience (hiri-ottappa) or the outward teachings you read about Buddhism?

I say go for it! If it is something that you feel will allow you to cultivate Right Livelihood (and this certainly sounds like it would), then act on those intentions. Of course there will be difficulties along the way, things that might challenge your commitment to sila. But the way I look at it is: our decision to honour sila is not a decision that we take once and for all. It is a decision that we have to take repeatedly, from moment to moment, day to day, as the reality of anicca brings forth different unexpected, unforeseen, unknown, and unknowable challenges from the future. Each time a challenge come our way is an opportunity to make a decision in the direction of the Dhamma. This decision, however, can never fully anticipate that which will always remain 'to come'. So over and over again we make the decision to honour our commitment to the Dhamma. For me, this repeated movement is what builds the momentum of faith, or if you don't like this word we'll leave it untranslated as saddha, one the five faculties we need to progress on the path. I would also say that it is this movement that gives us the strength to face whatever difficulties that come our way--and it seems like this chosen career path of yours, if it comes to fruition, would bring many challenges and difficulties. But these difficulties are precisely the point, isn't it?

Maybe Universities allow for cultural / religious convictions nowdays. You could ask to be exempted from actually having to place electrodes on those poor fruit flies, or genetically modify them, or whatever experimental thing they are going to do..maybe they will let you just take notes etc and observe others, and gather evidence that way, and thus pass that unit...just an idea.

Then the Blessed One, picking up a tiny bit of dust with the tip of his fingernail, said to the monk, "There isn't even this much form...feeling...perception...fabrications...consciousness that is constant, lasting, eternal, not subject to change, that will stay just as it is as long as eternity." (SN 22.97)